Method for representing an animated object

ABSTRACT

The invention relates to a method for representing an animated object. In a three-dimensional drawing program used to generate and animate objects, the model behavior of objects is calculated. For this purpose, sequences of individual objects are output at defined times and subsequently the sequence of the individual objects is jointed into an animation sequence. Surface changes of the object are simulated by way of additional texture animation and output. The animation sequence and the texture animation are then joined in a vector-based page description language, such as the 3D PDF program, and played at the same time. Based on the available sequence of the individual objects, a user can interactively modify the object animated in this way while playing back the animation sequence and the texture animation and change the viewing angle for the animated object. The animation sequence or the texture animation can likewise be configured as an infinite loop and thereby give the human user a dynamic view of the animated object.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of patent application Ser. No.13/265,071, filed Nov. 30, 2011; which was a § 371 national stage filingof international application No. PCT/DE2010/000391, filed Mar. 26, 2010,which designated the United States; this application also claims thepriority, under 35 U.S.C. § 119, of German patent application No. DE 102009 018 165.2, filed Apr. 18, 2009; the prior applications are herewithincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a method for representing an animated object.

The representation of graphical objects is one of the main uses ofcomputers with sometimes very large computer resources. Comprehensivecomputation operations are required, in particular, when simulating andrepresenting three-dimensional objects, for example during thecomputer-aided design (CAD) of objects and the subsequent simulation ofa particular object behavior. The object is conventionally created in acorresponding drawing program, for example a CAD program, and the objectbehavior is then simulated with respect to defined parameter properties.The simulation calculations may sometimes last for hours or even days onaccount of the comprehensive computation operations. The object whichhas been calculated in this manner can then be visualized in the drawingprogram, but any change in the view or parameters makes it necessary torecalculate the simulation of the object within the drawing program.

For example, DE 602 14 696 T2 thus describes the simulation of a flow offluids and a structural analysis in thin-walled three-dimensionalgeometries, the simulation being input as an outer skin with a finiteelement mesh.

Furthermore, DE 698 31 385 T2 describes a method and an arrangement forblending graphical objects using planar maps which are described in apage description language. For this purpose, sections of a pagedescription language representation are converted into a planar maprepresentation and are blended with the planar map representations ofthe graphical objects. The advantage is that planar maps allow a type ofrepresentation which is independent of the color space and theresolution.

U.S. Pat. No. 7,123,269 B1 likewise describes the modification of vectorobjects. After the user has selected particular sections of an imagewith a large number of vector objects, parameters of selectivelydetermined vector objects can be changed and the changed vector objectscan be represented again.

The laid-open specification US 2008/0303826 A1 discloses a method and asystem for the animated representation of objects corresponding to dataitems by means of an intuitive input language.

The problem with all solutions in the prior art is that an animatedobject can only ever be represented in the drawing program.Alternatively, an image sequence of the animated object can be exportedby the drawing program, in which case the image sequence and particularparameters of the image sequence, for example the viewing angle, cannotbe subsequently changed.

For example, the so-called 3D-PDF from Adobe Systems Incorporatedcontains, as standard, rudimentary animation functions which can be usedto animate bodies in the form of puppets. However, surface changes ofthe bodies cannot be changed, for example deformed, expanded or producedas a wave movement on the body, with the aid of the animation functions.In particular, it is currently not possible to interactively representthe disintegration of the body on account of external forces, forexample as melting or exploding, in the 3D-PDF format. Therefore, it iscurrently not possible to run a precalculated animation and tointeractively change the latter by superimposing object sequences andtextures or to interactively change the viewing angle of the animatedobject during animation.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the object of providing a fast andresource-saving method for representing an animated object, in whichcase the representation of the animated object can be interactivelychanged by a user.

The object is achieved by means of a method having the featuresaccording to claim 1. The invention provides a method for representingan animated object in the form of an animation sequence, in which asequence of individual objects is generated for each moment of theanimation sequence of the object. The individual objects fully depictthe object at the respective moment and may be two-dimensional orthree-dimensional representations of the object.

An object in the sense of the present invention is a two-dimensional orthree-dimensional graphical representation of a real or acomputer-generated item, for example a ship or a moving surface of thesea.

The individual objects are joined in succession for each moment and formthe principal part of the animation sequence of the object. The surfacechanges of the object are then calculated as a texture animation.Texture animations are two-dimensional effects of the three-dimensionalobject which are projected onto the surface of the three-dimensionalobject in a similar manner to a video projector. Surface changes in thesense of the inventions may be, for example, deformations of thesurface, material changes of the surface, liquid movements on or in theobject or lighting effects. Lighting conditions can be changed by meansof texture animation, as can color effects and two-dimensionalmovements, but not the shape and design of the three-dimensional object.The calculated surface changes as a texture animation are then projectedonto the object in the animation sequence. The impression of an animatedobject is produced for a human viewer by simultaneously running theanimation sequence as a sequence of the individual objects with thetexture animation on the object.

The simulation of the object on the basis of internal or external forcesis calculated using a three-dimensional animation program, for example“Blender” or “Lightwave3D”. Alternatively, the animation program mayalso be integrated inside a program with a vector-based page descriptionlanguage. As part of the representation of the simulation, the object isrepresented in a simple manner and the sequence of the individualobjects for defined moments is output. After the physical animationshave been calculated in a protracted manner, an animation sequence whichcan be played as a sequence of the three-dimensional individual objectsis obtained. Consequently, the viewing angle of the animated object canbe interactively moved. A plurality of such precalculated animationand/or texture sequences can be freely assembled and can be combinedwith one another via a controller in such a manner that the visualimpression of being able to change the physical properties of theanimated object to a limited extent is produced for a human viewer.

25 objects are advantageously produced per second, which is advantageouson account of the physiognomy of the eye and makes it possible for theviewer to sense the running animation sequence with texture animation ina jerk-free manner. These individual objects which are calculated in acomplicated manner are then played in succession at high speed. Theprinciple corresponds to the presentation of film which likewisesimulates a movement from a large number of still individual images byrapidly playing the latter.

A human viewer is provided with the impression of an animated object byintegrating the texture animation as a simulated change of the surfacesof the object with the simultaneous running of the individual objects.This animation sequence of the animated object, which has been combinedin this manner, requires less storage capacity on account of the reduceddata density in comparison with playback in the drawing program. Thismakes it possible to interactively represent the animated object sincethe respective individual objects are present in full and the textureanimations, for example in the form of a light or flow simulation, havelikewise been determined on the basis of the animated object. Therefore,when interactively changing the viewing angle of the animated object,there is no need to determine a new animation sequence in the drawingprogram with sometimes a high degree of computational complexity, aspreviously.

One advantageous refinement of the method provides for the sequence ofthe individual objects to be created using a vector-based drawingprogram and to be assembled to form the animation sequence using avector-based page description language. The individual objects areadvantageously output via the conventional export and/or storagefunctions of the vector-based drawing program. Alternatively, provisionis made for the individual objects to be filtered out from thevector-based drawing program and from the graphics memories used by thevector-based drawing program or to be recorded using grabbing softwaretools. In this case, the grabbing software tool may either be usedautonomously or is part of the program written in a vector-based pagedescription language.

In this case, the grabbing software tool may be part of the vector-baseddrawing program or may be a separate program, for example a so-calledgadget as a software application. The grabbing software tool has directaccess to the geometry memory, to the texture memory of the graphicscard and/or to the graphics output, for example in the OpenGL or DirectXoutput format, in order to filter out the individual objects there.

This makes it possible, for example, to combine the simulation of a shipin conjunction with an animation of sea waves in such a manner that theship is interactively viewed using a program written in a vector-basedpage description language. In one exemplary use of the method, a shipcan be created as an object in the “Lightwave3D” program. The shipobject is then illuminated and the resultant light simulation is storedin a graphics file, for example in the JPG format, with the result thatthe lighting moment can be recorded and can be projected, as a textureanimation, onto the animated object in the form of a ship as part of theanimation sequence. After the movement of the ship has been calculatedas a movement of the object, the sea waves surrounding the object arestored as further objects with an additional texture animation. Theresultant effects and interactions between the objects are simulated foreach moment and are stored as respective individual objects in simpleobject models. In this respect, the individual object and optionally apossibly associated texture animation for the respective object arestored for each individual object of the object “ship” and for allindividual objects of the objects “sea waves”.

The individual objects and texture animations stored in this manner inrespective files are now imported into a program with a vector-basedpage description language, for example the program “Acrobat 3D Toolkit”from Adobe Systems Incorporated. After the animated objects have beengrouped with respect to one another and the texture animations have beenprojected onto the objects, the animation sequence can be visualized.The animated objects are combined as a sequence of the individualobjects in the program with the vector-based page description language.Alternatively, the already existing sequence of the individual objectsis imported into the program with the vector-based page descriptionlanguage.

The texture animation of the object is advantageously created using thevector-based drawing program and is combined with the object using theprogram with the vector-based page description language. This has theadvantage that the sequence of the individual objects and the textureanimation are directly joined with the aid of programs with avector-based page description language and can be played in a mannervirtually independent of the platform. Particularly programs with avector-based page description language make it possible to represent theobjects in a manner independent of the platform.

One advantageous refinement of the method provides for the textureanimation of the object to be determined on the basis of a numericalsimulation and to be combined with the object using the vector-basedpage description language.

The calculation and simulation of the object behavior as an animationsequence or of the texture of the object as a texture animation arecarried out using corresponding basic equations, for example taking thelattice Boltzmann method as a basis for taking into account internal andexternal frictional forces for simulating liquid behavior. Liquids canthus be calculated in a physically correct manner in the sense of asimulation and allow the human viewer to be given a visual impression ofthe sequences connected with the animated objects and interactionsbetween the objects. For example, the flow behavior of different liquidsinside an object, for example inside a pipe, can be simulated.

The advantage is considered to be the fact that a further textureanimation is created as a background plane of the object using thevector-based drawing program and is combined with the object as abackground plane to form the animation sequence using the vector-basedpage description language. For this purpose, the background plane neednot have any objects to be animated but rather the animated object withtexture animation is projected against the background of an exclusivetexture animation. This dispenses with computation operations since noindividual objects have to be created and joined for the backgroundplane.

As a result of the fact that the texture animation is generatedindependently of the individual objects or the objects, the textureanimation can be interactively varied on the basis of predefinableboundary conditions and the respectively varied texture animation can beinteractively projected onto the animated object using the vector-basedpage description language. Changes in the texture animation, for examplelighting conditions or a changed material behavior, can thus beinteractively changed by the user or on the basis of specifications andcan then be projected onto the object to be animated. This makes itpossible not only to interactively view the animated object from allsides in a program with a vector-based page description language butalso to interactively change the texture animation in the program withthe vector-based page description language at the same time.

A viewing angle of the animated object is advantageously interactivelycontrolled using the vector-based page description language. Since theindividual objects are in the form of two-dimensional orthree-dimensional object bodies, the latter can also be viewed from allsides. Since the respective texture animations are likewise projectedonto the respectively associated objects, the viewing angle can also bechanged during the animation sequence of the animated object. Thischange in the viewing angle of the animation sequence of the animatedobject was not possible in previous object representations invector-based page description languages. For this purpose, it islikewise important for a light texture to be calculated on the basis ofthe object and to be projected onto the object on the basis of theviewing angle.

So that the representation of the animation sequence of the animatedobject can also be played when there are few computer resources, theobject is composed of polygons and/or triangles and/or non-uniformrational B-splines and/or voxels. Non-uniform rational B-splines (NURBSfor short) are mathematically defined curves or areas which are used tomodel any desired shapes in the field of computer graphics. Thegeometrical information is represented using geometrical elements whichare functionally defined piece by piece. Any desired technicalproducible or natural shape of an object or sections of an object can berepresented with the aid of NURBS.

The advantage is considered to be the fact that a first sequence ofindividual images of the object for a first animation sequence iscombined with a second sequence of individual images of the object for asecond animation sequence. As a result of the fact that a plurality ofanimation sequences of the object are provided, the animation sequencescan be played either at the same time or alternatively. Animationsequences can therefore be replaced with one another by the user duringthe playback operation. The user is therefore provided with extensivevariation possibilities within the vector-based page descriptionlanguage in conjunction with the interactive control of the viewingangle.

First surface changes for the first sequence of individual images of theobject are advantageously calculated as a first texture animation andsecond surface changes for the second sequence of individual images ofthe object are calculated as a second texture animation and are joinedwith the animation sequences using the vector-based page descriptionlanguage. This results in extensive possibilities for varying thetexture animations with respect to the animated object within thevector-based page description language. In conjunction with the presenceof alternative animation sequences as a sequence of individual objectswhich have been varied, extensive variations of the animated object,which either relate only to the surface of the animated object as atexture animation or even relate to the movement and the object per seas an animation sequence, can be carried out within the vector-basedpage description language.

Surface changes are respectively advantageously determined for aplurality of objects and/or the background plane and are joined usingthe vector-based page description language.

One advantageous refinement of the method provides for the first andlast individual objects of the animation sequence to be matched to oneanother in such a manner that an endless loop of the animation sequencecan be represented. The starting and end objects of the animationsequence are advantageously matched using a so-called loop editor. Theendless loop can also be used with respect to selected individualobjects in the central part of the animation sequence. The loop editorrepresents the calculated sequences of the individual objects inpictograms or as an object representation on a timeline—similar to avideo editing program or a node editor which is known from 3D animationprograms for the overview of the graphical programming of shaders, forexample. This is because there is the possibility of copying, deletingand cutting sequences of the individual objects in this case too. Anadditional window in which the animation sequence of the objectcurrently being animated runs is integrated in the loop editor. Thefirst window shows, in animated form, the region which is currentlybeing edited, and the second window shows the first individual objectand the last individual object in an overlapping manner, the startingand end individual objects being displayed in a semi-transparent andoverlapping manner. Optionally, the first ten individual objects and thelast ten individual objects may also be represented in animated form inorder to see where cutting is best. An additional function of the loopeditor enables automatic approach between the start and end of theendless loop.

As a result of the fact that a virtually seamless transition between thestarting individual object and the end individual object is defined, theanimation sequence can be played in a virtually endless manner withoutthe transitions from the end individual object to the startingindividual object being apparent to the human viewer. One advantageousrefinement of the method provides for corresponding boundary conditionsand/or parameters to already be set when simulating and generating thesequence of the individual objects in such a manner that the endindividual object of the animation sequence virtually corresponds to thestarting individual object.

If a transition from the end individual object to the startingindividual object of the animation sequence is not possible, theanimation sequence is divided into partial sequences. For example, whensimulating the flow of water through a curved pipe, the animationsequence can be such that the flowing of the water into the pipe is notrepeated within an endless loop. The water begins to run and runsthrough the pipe until the desired end of the animation sequence. In thecentral part of the animation sequence, water has already reached theend of the pipe and flows through the pipes, with the result that thereare presumably no longer any great changes in the flow properties andthis central sequence can therefore be repeated. In an end sequence ofthe animation sequence, the switching-off of the water and the emptyingof the pipe can then be represented as a sequence which cannot berepeated.

In the loop editor, the human viewer can define and configure thepartial sequences of the animation sequence on the basis of hisexperience in such a manner that the partial sequences which arepossibly configured in different ways form the animation sequence. Thesequence of the individual objects which is defined in this manner canbe played as desired within a program with a vector-based pagedescription language, for example as 3D-PDF or alternatively also otherplayback environments such as the “Silverlight” program from theMicrosoft Corporation or the “Flash” software tool from Adobe SystemsIncorporated. In addition, the sequence of the individual objects canalso be subsequently modified in the vector-based page descriptionlanguage. Further graphical optimizations, for example a polygonreducement, can likewise be carried out. The animation sequence createdin this manner can then be read into a program with a vector-based pagedescription language and can be used as a flash animation or in the formof a control file for an interactive three-dimensional object.

In addition to synchronizing the starting individual objects and the endindividual objects in an animation sequence, the respective texturesequence can be synchronously played in an endless loop, the first andlast individual objects of the animation sequence and the associatedsurface change as a texture of the first and last individual objectsbeing virtually identical. This provides the human viewer with thegreatest possible range of variation possibilities, with the resultthat, in addition to the possibility of selecting from a plurality ofanimation sequences, different texture animations for the respectivelyselected animation sequence can also be compiled by the human viewer inthe vector-based page description language.

One advantageous refinement of the method provides for the sequence ofthe individual images and/or the texture animation and/or the lighttexture to be displayed in a display unit.

In order to reduce the computational complexity for simulating anddetermining the individual objects for the animation sequence, onlysectional planes of the individual objects are determined on the basisof predefinable planes and are displayed on the basis of these planes.Even if the behavior of a three-dimensional object is intended to besimulated and animated, the animation sequence is composed only ofsections or sectional planes of the individual objects. This minimizesthe computational complexity and the data size of the animationsequence. Provision is made for different animation sequences to becreated with respect to different sectional planes and sections. Therespective sections or sectional planes of the individual objects canthen be viewed by a human viewer in a quick and simple manner byinteractively selecting the respectively desired animation sequence andthus the respectively desired sectional plane and it is possible toswitch back and forth between the individual animation sequences bymeans of the vector-based page description language.

The sequence of the individual objects and/or the texture animationis/are determined using a simulation unit. By virtue of the fact thatthe sequence of the individual objects and/or the texture animationdoes/do not have to be calculated using expensive and complex simulationprograms, it is possible to use a simulation unit tailored to theproblem to be simulated. Simulation programs require comprehensiveoperation and control which can only be carried out by specially trainedexperts. In contrast, the simulation unit can be designed in such amanner that only a minimum amount of storage space is required and theinput by a layman is also possible. For example, the parameter inputcarried out by the user can create a flow of water through a pipe,which, according to a simulation behavior, can meet a collision object(here the pipe), where the objects, in the form of water constituents,are then distributed according to the simulation. The real-timerepresentation is effected using particle points or voxels for rapidunderstanding or on the basis of predefined sectional planes of thecollision object. The collision object is precisely defined by locatingthe areas of polygons/triangles, that is to say by reading theboundaries of the collision object or by specifications from the user.

For this purpose, the user must open a toolbox and can then choosebetween different pipe cross sections, so-called “shapes”. The user thenspecifies a radius for the diameter of the pipe as a collision object orinteractively defines it using a graphical selection. The user thendraws the line through the pipe as a collision object. Curve tools,distributing guides and other tools are available for creating the path.The user can selectively choose the shapes using the toolbox.Alternatively, this task can be transferred to a computer which selectsthe shapes in an automated method.

The real-time preview of the animation sequence is then represented inthe path which has been created and the user can work with theparameterization. If the user is satisfied with the simulation, he canstart the complex three-dimensional simulation by pressing a button andthe animation sequence derived therefrom can be output. Optionally, theuser can also generate texture animations which are subsequentlyprojected onto the finished animation sequence.

The present method likewise makes it possible to import an area definedby the user, for example a water surface, into the simulation unit. Theuser can then input the necessary parameters, for example the winddirection and strength, and the simulation of a wave can thus becalculated. Additional objects such as ships can be placed on the watersurface. The wave movements produce further waves and spray. Theanimation sequence indicates geometries and textures for the roughpreview.

If the user is satisfied with the simulation, he can start the complexthree-dimensional simulation by pressing a button and the finishedanimation sequence can be output. With this form of simulation, theclosed water surface is broken up into sections; the spray first of allconsists of particles, polygons or volume objects such as “voxels” andis subsequently likewise broken up into sections. The impinging drops ofwater of the spray and the breaking waves are stored as textures on thewater surface. Both methods can be represented in real time separatelyor together using more modern and more powerful computers or maylikewise be exported and/or processed as 3D object sequences.

Selected properties for the surface simulations of the water surface,such as color or transparency, can likewise be changed by the user. Thewave movements of the water surface are created using so-called centersin which the waves arise. The method makes it possible for the wave toknow its volume, force and speed in order to carry out correct forcedistributions at further objects, such as a wall or a ship, so thateverything physically moves in a correct manner. Alternatively, a flashprogram can also be used to play the animation sequence.

The portable document format (PDF) data format is advantageously used asthe vector-based page description language. However, other platformssuch as Microsoft's “Silverlight”, Adobe's “Flash” etc. can also bealternatively used. The advantage is considered to be the fact that thedata size of the animation sequence is reduced to the image size of adisplay unit.

A computer program and a computer program product also achieve theobject, the computer program product being stored in a computer-readablemedium and comprising computer-readable means which cause a computer tocarry out the method according to the invention when the program runs inthe computer. The present invention may be implemented in the form ofhardware, software or a combination of hardware and software. Any typeof system or any other apparatus set up to carry out the methodaccording to the invention is suitable for this purpose. The presentinvention may also be integrated in a computer program product whichcomprises all of the features that enable it to implement thecomputer-assisted methods described here and which, after being loadedinto a computer system, is able to carry out these methods.

In the present context, the terms “computer program” and “computerprogram product” should be understood as meaning any expression in anydesired computer language, code or notation of a set of instructionswhich enable a computer system to process data and thus to perform aparticular function. The computer program or the computer programproduct can be executed on the computer system either directly or afterconversion into another language, code or notation or by means ofrepresentation in another material form.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Further advantageous refinements are found in the subclaims. The presentinvention is explained in more detail using the exemplary embodiments inthe figures, in which, by way of example,

FIG. 1 shows a flowchart with the essential method steps;

FIG. 2 shows a diagrammatic illustration of the essential method steps;

FIG. 3 shows a perspective view of an object with different sectionalplanes;

FIG. 4 shows a view of an object in a vector-based page descriptionlanguage program;

FIG. 5 shows a diagrammatic illustration of the essential method stepswith a preview program.

DESCRIPTION OF THE INVENTION

FIG. 1 shows a flowchart with the essential method steps. After themethod has been started, the object 1 (not illustrated) is simulated 10.In a drawing program 5 (not illustrated), for example Lightwave3D, or ina simulation unit, the behavior of the object 1 is simulated and isgenerated in temporally successive individual objects 2 a, 2 b, 2 c, 2d, 2 e, 2 f, 2 g (not illustrated).

In addition, the texture of the animated object 1 is generated andsimulated 12 either in the drawing program 5 or by means of a separateeditor 6 (not illustrated) and is stored as a texture animation 4 a, 4 b(not illustrated). Alternatively, the texture animation can also besimulated 12 in a parallel manner to the simulation of the object 10 orcompletely independently of the simulation of the object 10. Theindividual objects are then joined 13, as a temporal sequence, to forman animation sequence 3 a, 3 b (not illustrated). Alternatively, theindividual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g may also beindividually read from the drawing program 5 and then viewed in afurther preview program 17 (not illustrated) as a previewer and/or canbe assembled as a sequence and thus as an animation sequence 3 a, 3 b.The texture animation 4 a, 4 b is then projected 14 onto the animationsequence 3 a, 3 b and thus depicts the surface changes of the animatedobject 1. The playback of the animation sequence 3 a, 3 b with thetexture animation 4 a, 4 b is repeated using a loop operation 16 untilan internal condition occurs or a human viewer terminates the process.

FIG. 2 illustrates a diagrammatic illustration of the basic methodsequences. In the drawing program 5, the individual objects 2 a, 2 b, 2c are generated and the temporal behavior is simulated. In the drawingprogram 5, the individual objects 2 a, 2 b, 2 c are already joined, as asequence, to form an animation sequence 3 a. The animation sequence 3 ais indicated by the vertical lines between the individual objects 2 a, 2b, 2 c and is intended to indicate the temporal sequence of theindividual objects 2 a, 2 b, 2 c. In a further program 6, the texturesare connected to form a texture animation 4 a, the texture animation 4 aagain being indicated by the vertical lines between the textures. Theanimation sequence 3 a and the texture animation 4 a are loaded into aprogram with a vector-based page description language 7 and can beplayed in a display unit 18 by means of control elements 8 a, 8 b. Thehuman user can use the control elements 8 a, 8 b to control the courseand speed of the animation sequence 3 a with the texture animation 4 a.

FIG. 3 shows a perspective view of an object 1 with different sectionalplanes 9 a, 9 b, 9 c, 9 d, in which case not all sectional planesillustrated are assigned to a figure designation for the sake ofclarity. The animation sequence 3 a, 3 b (not illustrated) and thetexture animation 4 a, 4 b, 4 c (not illustrated) are calculated on thebasis of a simulation for the entire object 1. However, the actualanimations 3 a, 3 b, 4 a, 4 b, 4 c are only illustrated and projectedfor predefinable sectional planes 9 a, 9 b, 9 c, 9 d, 9 f, 9 g. In theexample shown in FIG. 3, three radially running sectional planes 9 a, 9b, 9 c subdivide the interior of a tubular object 1. Furthermore, threeaxially running sectional planes 9 d, 9 f, 9 g run inside the pipe as anobject 1. The animation sequence 3 a, 3 b and the texture animation 4 a,4 b, 4 c are output only for the sectional planes 9 a, 9 b, 9 c, 9 d, 9f, 9 g, which requires only small computation capacities.

The three-dimensional simulation behavior of the animated object 1 canbe represented in two dimensions by representing a three-dimensionalobject behavior in the two-dimensional sectional planes 9 a, 9 b, 9 c, 9d, 9 f, 9 g—if appropriate on the basis of automatic detection of theobject geometries during the simulation 10. A path to which the 2Dtextures of the fluid simulation of the animation sequence 3 a, 3 b,which functions in real time, can be tied is automatically createdduring the simulation 10.

Overall, depending on the computer capacity, a plurality of such “2Dslices” as sectional planes 9 a, 9 b, 9 c, 9 d, 9 f, 9 g are placed inthe pipe as an object 1 and are horizontally and vertically interleaved.In the case of 3×3 sectional planes 9 a, 9 b, 9 c, 9 d, 9 f, 9 g, as inthe example shown in FIG. 3, nine animation sequences 3 a, 3 b and/ortexture animations 4 a, 4 b, 4 c are thus created and therefore, incombination, provide a user with a very realistic three-dimensionalimpression of the behavior of the animated object.

FIG. 4 shows an excerpt from an animation sequence 4 a (not illustrated)of the animated object 1. In the example shown in FIG. 4, the objectbehavior of the static pipe does not need to be calculated. The mediumflowing through the pipe is simulated using a simulation and is storedas individual objects 2 a, 2 b, 2 c. The surface change of the liquidwhen flowing through the pipe is then simulated and stored as a textureanimation 4 a, 4 b. In the program with the vector-based pagedescription language, for example 3D-PDF or Microsoft's “Silverlight” orAdobe's “Flash”, the animation sequence 3 a, 3 b and the textureanimation 4 a, 4 b, 4 c can then be joined and played. On account of thesimple type of programming, it is also possible to define buttons andicons as control elements 8 a, 8 b in the vector-based page descriptionlanguage, which control elements make it possible to play the animationsequence 3 a, 3 b with the texture animation 4 a, 4 b, 4 c. At the sametime, the human viewer can use the control elements 8 a, 8 b tointeractively change the viewing angle of the animated object 1.

FIG. 5 shows a diagrammatic illustration of the essential methodsequences with a preview program 17. In the drawing program 5, theindividual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g are generated onthe basis of a simulation predefined by the user. Corresponding textureswith regard to the surface changes of the individual objects 2 a, 2 b, 2c, 2 d, 2 e, 2 f, 2 g are determined in the further program 6. Thetemporal sequence of the respectively associated individual objects 2 a,2 b, 2 c, 2 d, 2 e, 2 f, 2 g can be viewed in the preview program 17, auser then being able to generate an animation sequence 3 a, 3 b fromthis preview. The sequence of the textures can likewise be viewed and atexture animation 4 a, 4 b, 4 c can then be created. The animationsequences 3 a, 3 b and the texture animations 4 a, 4 b, 4 c are thenloaded into the program with the vector-based page description language7 and can be played in a display unit 18 using control elements 8 a, 8b. In this case, during the running of a first animation sequence 3 a, 3b with a first texture animation 4 a, 4 b, 4 c, the user is likewiseable to interactively mutually combine the animation sequence 3 a, 3 band/or the texture animation 4 a, 4 b, 4 c and to view it/them fromdifferent viewing angles. A simulation unit in which the individualobjects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g generated in the drawingprogram 5 and/or the textures generated in the further program 6 aresimulated may likewise be integrated in the preview program 17.

In the program with the vector-based page description language 7, theuser starts a program or a plug-in and imports the individual objects 2a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g using Adobe Acrobat 3D Toolkit or as anOBJ file or as further supporting file formats.

For example, in the case of simulation of the flow through a pipeaccording to the examples in FIG. 3 and FIG. 4, the user is then able todefine the pipe as an object 1 and selects, for example, the radius ofthe pipe and the resolution of the further objects as volume bodies ofthe fluid. The user can then view a corresponding preview of theindividual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g and/or of thetextures and the temporal sequence of the individual objects 2 a, 2 b, 2c, 2 d, 2 e, 2 f, 2 g and/or of the textures in the preview program 17in a display unit. For this purpose, the model behavior of theindividual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g and/or of thetextures is calculated for a plurality of sectional planes 9 a, 9 b, 9c, 9 d, 9 e, 9 f and is represented in the three-dimensional pipe as anobject 1 by means of a real-time preview.

Furthermore, the parameters and properties of the fluid can beinteractively changed during the preview. There is also a standardsetting which adopts materials such as water, oil or gases into theparameter setting at the click of a mouse. While the user is making hisparameter input, he can see, in the preview program 5 in real time, howthe settings directly change in the previewer. The user can likewisealso set and interactively change the type of textures. When the user issatisfied with the setting, he presses a button “Create 3D sequence” andmust also specify the formula according to which he would like to havethe physical simulation calculated. All parameters are then adopted intothe 3D engine and the animation sequence 3 a, 3 b either with or withouta texture animation 4 a, 4 b, 4 c is calculated 13, 14 from polygons,particles and/or volume models such as voxels. The animation sequences 3a, 3 b and/or texture animations 4 a, 4 b, 4 c calculated in this mannerare stored. The animation sequences 3 a, 3 b and/or texture animations 4a, 4 b, 4 c are then edited in the loop editor in such a manner that astarting part, a central part and an end part of the animation sequences3 a, 3 b and/or texture animations 4 a, 4 b, 4 c are available and canbe loaded into the 3D-PDF program or into other platforms such asMicrosoft's “Silverlight” or Adobe's “Flash”. If necessary, the centralpart of the animation sequences 3 a, 3 b and/or texture animations 4 a,4 b, 4 c can be run through again in certain loops. In order to reducethe file size of the animation sequences 3 a, 3 b and/or textureanimations 4 a, 4 b, 4 c, the user uses the function of the objectdetail reduction in the loop editor to reduce the resolution of theindividual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g and/or of theanimation sequence 3 a, 3 b and/or of the texture animation 4 a, 4 b, 4c. Definitive animation sequences 3 a, 3 b and/or texture animations 4a, 4 b, 4 c are now automatically created using a control element 8 a, 8b and are directly created in the program with the vector-based pagedescription language, for example 3D-PDF.

The user can track his changes to the individual objects 2 a, 2 b, 2 c,2 d, 2 e, 2 f, 2 g and/or to the animation sequence 3 a, 3 b and/or tothe texture animation 4 a, 4 b, 4 c on the freely defined fluid flow orocean current interactively and in real time. Although the technologieson the market, for example “Next Limits” or “RealFlow”, make it possiblefor the user to parameterize the objects 1 as fluids, there is no realpreview which allows the user to directly discern, with 25images/second, what sort of effects the parameter changes have on thebehavior of the individual objects 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 gand/or of the animation sequence 3 a, 3 b and/or of the textureanimation 4 a, 4 b, 4 c. In such programs, there is a need for atime-consuming preview simulation which is then cached in order to showit to the user. If he changes the parameters, the entire simulation mustbe recalculated, sometimes with a considerable expenditure of time.

Provision is likewise made for the graphical data format, for examplethe OpenGL or the DirectX format, to be able to be used inside thedrawing program 5 and/or the further program 6 and for the change in thesurface colors to be able to be graphically represented in real time andthus observed by a viewer. These surface colors can be seen only when abutton for the visibility of properties has previously been activated.If, for example, a ball as an animated object 1 is intended to bechanged, the animation function changes the color of the selected ballas an animated object 1 to red. It is therefore possible to discernwhich objects 1 or object parts are currently running on the basis ofthe selection using the animation function. Blue could stand for watersimulation with a large number of objects 1, green could stand for themasking of an object 1, pink stands for an object 1 which will collide,and pink-red stands for an object 1 which has its own deformation.

The present method also makes it possible to simulate film and gamingapplications. The drawing program 5, 6 is used to create a percentage 3Dmap of hairs which are defined as objects 1. In order to be able torepresent the hairs as objects 1 in real time, a multiplicity ofsectional planes 9 a, 9 b, 9 c, 9 d, 9 e, 9 f are placed through thevolume hair. The sectional planes 9 a, 9 b, 9 c, 9 d, 9 e, 9 f piercethe hairs to be modeled and leave behind a cross section of the hairwhich has just been cut on their 2D plane. This cross section isrepresented by the drawing program 5. Everything which has not been cutis transparent. Fanned out from the hairline to the tip of the hair,fifteen two-dimensional sectional planes 9 a, 9 b, 9 c, 9 d, 9 e, 9 fwhich are distributed along the hairs thus depict the hairs with therespective cross section of a hair and a texture.

There is also another variant for creating hairs in real time. For thispurpose, in a base plate as an object 1 with small holes. This baseplate as an object 1 moves very quickly from one point to the next. Inthis case, motion blur is switched on during the simulation 10. Theholes in the base plate as an object 1 remain free because there canalso be no motion blur where there is air. For this purpose, only everysecond individual object 2 a, 2 b, 2 c, 2 d, 2 e, 2 f, 2 g is calculatedso that it is not possible to discern any flowing movement from onepoint to the next. The impression that the motion blur “is stationary”and is not moving is thus produced. As a result of the effect, itappears as if grass is growing from the base plate as an object 1.

1. A method for representing an animated object in the form of ananimation sequence, having the following steps of: generating a sequenceof individual objects for each moment of the animation sequence of theobject; joining the individual objects for each moment to form theanimation sequence; calculating surface changes of the object as atexture animation; projecting the texture animation onto the object inthe animation sequence; simultaneously running the animation sequencewith the texture animation and thus generating the impression of ananimated object; interactively controlling a viewing angle of theanimated object using a program with a vector-based page descriptionlanguage; and reducing a data size of the animation sequence to an imagesize of a display unit.
 2. The method according to claim 1, whichcomprises using a Microsoft Silverlight data format as the vector-basedpage description language.
 3. The method according to claim 1, whichcomprises using an Adobe Flash data format as the vector-based pagedescription language.
 4. The method according to claim 1, whichcomprises interactively moving the viewing angle of the animated objectafter calculating physical animations in a protracted manner.
 5. Themethod according to claim 1, which comprises: obtaining an animationsequence that is played as a sequence of the individual objects, whereinthe individual objects in the sequence of the individual objects that isplayed are three-dimensional; and interactively moving the viewing angleof the animated object after obtaining the animation sequence.
 6. Themethod according to claim 1, which comprises performing the step ofreducing the data size of the animation sequence by a graphicaloptimization implemented as a polygon reducement, wherein a surface ofthe animated object is composed of a plurality of polygons.
 7. Themethod according to claim 1, wherein the sequence of the individualobjects is created using a drawing program and is assembled to form theanimation sequence with texture animation of the object using theprogram with the vector-based page description language.
 8. The methodaccording to claim 1, wherein the texture animation of the object iscreated using the drawing program and is combined with the object usingthe program with the vector-based page description language.
 9. Themethod according to claim 1, wherein the texture animation of the objectis determined on the basis of a numerical simulation and is combinedwith the object using the program with the vector-based page descriptionlanguage.
 10. The method according to claim 1, wherein a further textureanimation is created as a background plane of the object using thedrawing program and is combined with the animation sequence as abackground plane of the object using the program with the vector-basedpage description language.
 11. The method according to claim 1, whereinthe texture animation is varied on the basis of the interactivevariation of predefinable boundary conditions and the respectivelyvaried texture animation is interactively projected onto the animatedobject using the program of the vector-based page description language.12. The method according to claim 1, wherein a light texture iscalculated on the basis of the object and is projected onto the objecton the basis of the viewing angle.
 13. The method according to claim 1,wherein the object is composed of polygons and/or triangles and/ornon-uniform rational B-splines and/or voxels.
 14. The method accordingto claim 1, wherein a first sequence of individual objects for a firstanimation sequence of the object is combined with a second sequence ofindividual objects for a second animation sequence of the object. 15.The method according to claim 14, wherein first surface changes for thefirst sequence of individual objects are calculated as a first textureanimation and second surface changes for the second sequence ofindividual objects are calculated as a second texture animation and arejoined with the animation sequences of the object using the program withthe vector-based page description language.
 16. The method according toclaim 1, wherein surface changes are respectively determined for aplurality of objects and/or the background plane and are joined usingthe program with the vector-based page description language.
 17. Themethod according to claim 1, wherein the first and last individualobjects of the animation sequence are matched to one another in such amanner that an endless loop of the animation sequence of the object canbe represented.
 18. The method according to claim 17, wherein theanimation sequence and the texture animation are synchronously played inan endless loop, the first and last individual objects of the animationsequence and the associated surface change as a texture animation of thefirst and last individual objects being virtually identical.
 19. Themethod according to claim 1, wherein the sequence of the individualobjects and/or the texture animation and/or the light texture is/aredisplayed in a display unit.
 20. The method according to claim 1,wherein the individual objects are determined on the basis ofpredefinable planes and are displayed on the basis of these planes inthe animation sequence of the object.
 21. The method according to claim1, wherein the individual objects and/or the texture animation is/aredetermined using a simulation unit.
 22. The method according to claim 1,wherein the portable document format (PDF) data format is used as thevector-based page description language.